The field of the present invention relates generally to light sources.
An aircraft is required by law to have forward position lights, including a green light on the starboard side or right side of the aircraft and a red light on the port or left side of the aircraft. The lights are typically positioned at the leading edge of each of the aircraft""s wings apart laterally from one another as far apart as practicable. Their function is to enable observers of the aircraft to determine the position and orientation of the aircraft and the direction in which it is traveling.
Forward position lights are subject to strict requirements or standards defined in the Federal Aviation Regulations which can be found in Title 14 Subchapter C of the United States Code of Federal Regulations, which is hereby incorporated by reference. Section 25.1381 through section 25.1397 of Part 25 of Subchapter C is attached to this application as Attachment A. In part, these regulations require that each aircraft forward position light comply with minimum candela (cd) outputs while maintaining defined chromaticity or color quality. In addition, the regulations require the light sources to comply with certain structural integrity criteria including criteria relating to shock, shear load, vibration, leakage and surface temperature. Industry standards for aircraft design have exacted additional design limitations. For example, traditionally aircraft design has dictated a 28-volt power supply to power the aircraft forward position lights. In addition, with respect to replacement light sources, consideration must be made of the further limitations imposed by the existing design envelopes (i.e., dimensional considerations). Moreover, it is generally advantageous that the light source be as compact in design as possible so that it may be mounted at the leading edges of the wing tips without imposing a burden to the aerodynamics of the aircraft.
Presently, specially designed incandescent light bulbs are employed as light sources for aircraft forward position lights. While the technology underlying the use of incandescent lights is familiar, there are a number of shortcomings that make their use in this application less than ideal. For example, the incandescent light sources adapted for this use are presently understood to typically have a life expectancy of 2,500 to 5,000 operating hours. After which time they must be replaced, thereby, incurring maintenance costs related to labor, replacement parts, and inventory overhead and storage.
In addition, incandescent light sources emit white or polychromatic light. As such, to achieve the required color quality for use as an aircraft position light, specially designed colored lenses are needed to filter the polychromatic light to the required chromaticity or color quality. Thus, wasted power is expended in the emission of unusable light, which consequently increases the probability of heat damage to the surrounding components and housing structure.
Furthermore, it is presently understood that incandescent light sources traditionally employ a single lighting filament or alternatively multiple lighting filaments electrically connected in series. Consequently, the failure of any one filament results in the complete failure of the light source. Such an all-out failure may result in a reduced level of safety in the airways, especially if the failure of the light source occurs in mid-flight when replacement of the light source is not possible.
Therefore, it is desirable to provide a light source that overcomes one or more of the foregoing shortcomings more successfully than those known in the art while maintaining or exceeding the standards imposed by law.
The present invention relates in one aspect to the light emitting diode (LED) clusters suitable for use as aircraft forward position light sources.
According to one aspect as described herein, the aircraft forward position light source comprises, a base structure, and multiple LED components mounted on a defined region of the base structure, and adapted so that, when powered, the LED components emit light that meets the candela output design criteria defined in Table 1 and Table 2 and the Federal Aviation chromaticity requirements for the light source.
According to another aspect, the aircraft forward position light source comprises a base structure, electrical circuitry adapted to be connected to a power supply, and at least four sets of LED components mounted on a defined region of the base structure and in electrical communication with the electrical circuitry with a first LED component set being oriented at a first defined angle distally relative normal, a second LED component set being oriented substantially normal, a third LED component set being oriented at a third defined angle downwardly relative to normal, and a fourth LED component set being oriented at a fourth defined angle upwardly relative to normal such that, when powered the LED components emit light that meets the candela output design criteria defined in Table 1 and Table 2.
According to yet another aspect as described herein, the aircraft forward position light source comprises multiple LED components adapted to being in full compliance with both the candela output design criteria defined in Table 1 and Table 2 and the Federal Aviation chromaticity requirements for the light source, the LED components being further adapted to fall within the confines of a defined area of approximately 2.75 inches by 2.00 inches.
Additional implementations, features, variations and advantages of the invention will be set forth in the description that follows, and will be further evident from the illustrations set forth in the accompanying drawings.